Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Neurological impairment
Systematic review	675 infants with evidence of perinatal asphyxia and hypoxic–ischaemic encephalopathy 7 RCTs in this analysis	Rate of adverse neurological sequelae 43/332 (13%) with hyperbaric oxygen 84/317 (26%) with control	OR 0.41 95% CI 0.27 to 0.61	Moderate effect size	hyperbaric oxygen